Abstract
A promoter of the PNZIP (Pharbitis nil leucine zipper) gene (1.459 kb) was
cloned from Pharbitis nil and fused to the GUS (β-glucuronidase) and Bacillus
thuringiensis endotoxin (Cry9C) genes. Several transgenic PNZIP::GUS and PNZIP::Cry9C cotton lines were developed by
Agrobacterium-mediated transformation. Strong GUS staining was detected in the
green tissues of the transgenic PNZIP::GUS cotton plants.
In contrast GUS staining in the reproductive structures such as petals, anther, and immature seeds of PNZIP::GUS cotton was very faint. Two transgenicPNZIP::Cry9C
lines and one transgenic cauliflower mosaic virus (CaMV) 35S::Cry9C line were selected for enzyme-linked immunosorbent assay (ELISA) and insect bioassays. Expression of the Cry9C protein in the 35S::Cry9C line maintained a
high level in most tissues ranging from 24.6 to 45.5 μg g(-1) fresh weight. In green tissues such as the leaves, boll rinds, and bracts of the PNZIP::Cry9C
line, the Cry9C protein accumulated up to 50.2, 39.7, and 48.3 μg g(-1) fresh
weight respectively. In contrast, seeds of the PNZIP::Cry9C line (PZ1.3)
accumulated only 0.26 μg g(-1) fresh weight of the Cry9C protein, which was 100
times lower than that recorded for the seeds of the CaMV 35S::Cry9C line. The
insect bioassay showed that the transgenic PNZIP::Cry9C cotton plant
exhibited strong resistance to both the cotton bollworm and the pink
bollworm. The PNZIP promoter could effectively drive Bt toxin
expression in green tissues of cotton and lower accumulated levels of
the Bt protein in seeds. These features should allay public concerns
about the safety of transgenic foods. We propose the future utility
of PNZIP as an economical, environmentally friendly promoter in cotton biotechnology.
http://www.ncbi.nlm.nih.gov/pubmed/26728504
DOI: 10.1007/s11427-015-4920-6 (IF: 1.7)
PMID:
26728504